The scanty remains of Kenfig Castle, a once great medieval fortress, rise from the dunes beside the Cynfig river. The castle was established in the early twelfth century by the lord of Glamorgan and was set at the northern end of a walled borough (NPRN 15335). The castle was several times assaulted and ravaged and was greatly altered and added to in the late thirteenth century. It was maintained throughout the fourteenth century but was ruinous by the early sixteenth. The borough became besanded through the fifteenth century. The site was excavated in 1924-32.
The castle was set on a low knoll washed by the river on the west and north. It originally consisted of a roughly circular embanked and palisaded court some 37m across, enclosing a magnificent square-plan tower as well as a hall and its offices. The facades of the 14m square tower were articulated by slim dressed stone buttresses at the corners and centre of each side. It would have risen high above the court dominating the borough skyline. In about 1300 the castle was substantially reconstructed. The rampart was thrown down to level up the court and a stout curtain wall was built in its stead with a large masonry gatehouse facing into the borough. The tower was also reconstructed and its south-west wall completely rebuilt.
Source: RCAHMW Glamorgan Inventory III.1a 'The Earlier Castles' (1991), 314-325
John Wiles, RCAHMW, 13 February 2008